How much can herbal medicine improve survival in lung cancer on targeted therapy? — Nationwide Taiwan data from 1,988 patients showing a 68% lower risk of death

In lung cancer too — even for patients on the most advanced targeted therapy — herbal medicine is beneficial. Today we sum up this topic with a single large-scale nationwide cohort study from Taiwan.

Across the papers in our ongoing "Cancer" series, the type of cancer studied differs, yet they all arrive at the same conclusion. The lung cancer study introduced here likewise shows the same result. Lung adenocarcinoma patients who added herbal medicine to standard treatment had a markedly lower risk of death than patients who did not take herbal medicine. In particular, the longer the herbal medicine was taken, the greater the effect became.

How much can herbal medicine help survival in lung cancer on targeted therapy?

For advanced lung adenocarcinoma with an EGFR gene mutation, targeted drugs such as gefitinib and erlotinib (EGFR-TKIs) are used as first-line therapy. The response is dramatic at first, but over time the cancer cells develop resistance and the drug stops working — this is the biggest wall in targeted therapy. That is why "how to extend the period during which targeted therapy keeps working" is such an important question.

Published in 2019 in the international journal Integrative Cancer Therapies, this study drew on Taiwan's nationwide health insurance data (the catastrophic illness registry database), following patients newly diagnosed with advanced lung adenocarcinoma who began first-line targeted therapy between 2006 and 2012, tracked until 2013. Among 1,988 patients with EGFR-mutated advanced lung adenocarcinoma, it compared 217 patients who added herbal medicine with 1,771 who did not.

After adjusting together for multiple factors (age, sex, income, comorbidities, treatment after progression, and response to targeted therapy), patients who added herbal medicine for 180 or more days had a 68% lower risk of death than those who did not (hazard ratio 0.32, 95% confidence interval 0.21–0.50). In the survival curve (Kaplan-Meier) analysis, the herbal medicine group also had a higher probability of survival (P<0.001).

The longer the herbal medicine was taken, the clearer the effect

This study, like the papers introduced earlier, shows that the longer herbal medicine was taken, the more clearly its benefit grew. In patients who took it for 30–180 days no clear statistical difference had yet appeared (hazard ratio for death 0.80), but in patients who took it beyond 180 days the risk of death fell by up to 68%. This trend of falling risk with longer duration of use was also statistically very strong (trend test P<0.0001).

Just as cutting down only the diseased trees is a brief, one-off intervention while changing an entire ecosystem is a long-term undertaking, herbal medicine too can be understood as bringing greater real benefit when it steadily reshapes the body's ecosystem through long-term use.

Delaying resistance — and comparing only patients for whom the drug was still working

This study looked not only at survival but also at the time until the disease progressed again. Patients who added herbal medicine for 180 or more days had a 59% lower risk of disease progression (hazard ratio 0.41, 95% confidence interval 0.29–0.58). The greatest wall in treating lung adenocarcinoma is that targeted therapy eventually meets resistance and stops working — and in patients who added herbal medicine, the point of hitting that wall was clearly pushed back.

There is one more reason this result is especially trustworthy. The researchers excluded 179 patients who started herbal medicine only after the tumor had already progressed. By keeping only patients who used herbal medicine while targeted therapy was still working, the study headed off the common misconception that "patients who were already worsening simply grasped at herbal medicine as a last resort."

Don't put off the benefits of herbal medicine any longer

Like other studies, this one once again clearly shows that the effect becomes even more evident when herbal medicine is added to standard therapy. In particular, we must remember that the effect was maximized when herbal medicine was continued steadily over a long period. If you are receiving — or about to begin — targeted therapy for lung cancer, especially EGFR-mutated lung adenocarcinoma, we close by encouraging you to consult thoroughly with a Korean-medicine specialist and steadily continue an herbal medicine prescription suited to you.